Follow these steps:

Go to Help, Install New Software.Add,Archive and select the downloaded file.

Use the Plugin

To get started with Tasktop Dev for CA Agile Central for Eclipse, select the CA Agile Central button on the toolbar and follow the steps on the dashboard. A CA Agile Central page located under the My Home page. Panels on the dashboard display various information and charts. Users can control what panels display and how they appear. You can create multiple dashboards as custom pages.